2 Samuel 5:4

5:4 David was thirty years old when he began to reign and he reigned for forty years.

2 Samuel 19:31

19:31 Now when Barzillai the Gileadite had come down from Rogelim, he crossed the Jordan with the king so he could send him on his way from there. ¹ 

[19:31]  ¹ tc The MT reading אֶת־בַיַּרְדֵּן (’et-vayyarden, “in the Jordan”) is odd syntactically. The use of the preposition after the object marker אֶת (’et) is difficult to explain. Graphic confusion is likely in the MT; the translation assumes the reading מִיַּרְדֵּן (miyyarden, “from the Jordan”). Another possibility is to read the definite article on the front of “Jordan” (הַיַּרְדֵּן, hayyarden; “the Jordan”).